A concrete example

A concrete example of how cognitive psychology can aide designers: Fitts’ Law.
A fairly straightforward law regarding our motor skills: small targets are harder to hit than large ones / it takes longer to hit targets that are further away. There’s a nice, uncomplicated formula to go with the law: MT = a + b log2(2A/W).

Simple as the theory might be, the implications for GUI design are large. Fitts’ law gives us the chance to predict how hard or easy it is to move a mouse pointer to a button or menu item. It also shows us that there are ‘magic spots’ that are easiest to reach with a mouse. First, the place the mouse pointer is right now is the easiest spot to reach. Second, the edges of the screen have infinite width: the mouse pointer does not have to slow down to hit it. That makes the screen edge the obvious location for much-used functionality. And third, the corners of the screen have infinite width in two directions. The screen corners would be a logical place for important functions.

None of the major operating systems optimize for this knowledge. The Magic Pixel is now commonly used for contextual menus, but the screen corners are hardly used for important functionality (obviously, the problem there is how to give the user visual feedback on the available functions in the corners).

Knowing Fitts’ law, why do the toolbars in Adobe Creative Studio apps have a non-clickable, 1-pixel edge? And why are Windows menus on the window edges and not on the edge of the screen? Knowledge of cognitive psychology could improve the usability of many interactive applications.A concrete example of how cognitive psychology can aide designers: Fitts’ Law.
A fairly straightforward law regarding our motor skills: small targets are harder to hit than large ones / it takes longer to hit targets that are further away. There’s a nice, uncomplicated formula to go with the law: MT = a + b log2(2A/W).

Simple as the theory might be, the implications for GUI design are large. Fitts’ law gives us the chance to predict how hard or easy it is to move a mouse pointer to a button or menu item. It also shows us that there are ‘magic spots’ that are easiest to reach with a mouse. First, the place the mouse pointer is right now is the easiest spot to reach. Second, the edges of the screen have infinite width: the mouse pointer does not have to slow down to hit it. That makes the screen edge the obvious location for much-used functionality. And third, the corners of the screen have infinite width in two directions. The screen corners would be a logical place for important functions.

None of the major operating systems optimize for this knowledge. The Magic Pixel is now commonly used for contextual menus, but the screen corners are hardly used for important functionality (obviously, the problem there is how to give the user visual feedback on the available functions in the corners).

Knowing Fitts’ law, why do the toolbars in Adobe Creative Studio apps have a non-clickable, 1-pixel edge? And why are Windows menus on the window edges and not on the edge of the screen? Knowledge of cognitive psychology could improve the usability of many interactive applications.A concrete example of how cognitive psychology can aide designers: Fitts’ Law.
A fairly straightforward law regarding our motor skills: small targets are harder to hit than large ones / it takes longer to hit targets that are further away. There’s a nice, uncomplicated formula to go with the law: MT = a + b log2(2A/W).

Simple as the theory might be, the implications for GUI design are large. Fitts’ law gives us the chance to predict how hard or easy it is to move a mouse pointer to a button or menu item. It also shows us that there are ‘magic spots’ that are easiest to reach with a mouse. First, the place the mouse pointer is right now is the easiest spot to reach. Second, the edges of the screen have infinite width: the mouse pointer does not have to slow down to hit it. That makes the screen edge the obvious location for much-used functionality. And third, the corners of the screen have infinite width in two directions. The screen corners would be a logical place for important functions.

None of the major operating systems optimize for this knowledge. The Magic Pixel is now commonly used for contextual menus, but the screen corners are hardly used for important functionality (obviously, the problem there is how to give the user visual feedback on the available functions in the corners).

Knowing Fitts’ law, why do the toolbars in Adobe Creative Studio apps have a non-clickable, 1-pixel edge? And why are Windows menus on the window edges and not on the edge of the screen? Knowledge of cognitive psychology could improve the usability of many interactive applications.